What is CVE-2018-5721?

CVE-2018-5721 is a high-severity vulnerability in Asuswrt-Merlin, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2018-01-17.

How severe is CVE-2018-5721?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2018-5721 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Asuswrt-Merlin

CVE-2018-5721

Stack-based buffer overflow in the ej_update_variables function in router/httpd/web.c on ASUS routers (when using software from https://github.com/RMerl/asuswrt-merlin) allows web authenticated attackers to execute code via a request that updates a setting. In ej_update_variables, the length of the variable action_script is not checked, as long as it includes a "_wan_if" substring.

Vulnerability class: Buffer Overflow

EPSS: 0.019 (78.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Asuswrt-merlin
N/a — versions n/a

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2018-5721?: CVE-2018-5721 is a high-severity vulnerability in Asuswrt-Merlin, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2018-01-17.
How severe is CVE-2018-5721?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2018-5721 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.